...the unpopularity of the suit didn't sneak up on anyone.
My sense is that the decision to sue is, above all, an ideological one. Certainly, the point man on the suit, DOJ Civil Rights Division head Tom Perez, is a long-time advocate on behalf of illegal immigrants
This is an administration that won't back down on its core beliefs. One of its core beliefs is that illegal immigrants should not be bothered by the police. Another is that millions of illegal immigrants should receive amnesty (a belief that is, of course, supported by long-term poltical interests). Vindicating the latter objective requires that the federal government determine just how much immigration enforcement (or more precisely, how little) will occur in the absence of "comprehensive reform," i.e., amnesty.
Public opinion and short-term political considerations no more influence the administration's behavior on immigration than they did on health care.
In fact, it's just what I said already myself here and here and here.
I see that "Paul" (Mirengoff) must have overlapped with me at Stanford, and for some mysteriours reason "supports Everton FC of the English Premier soccer League" along with many of my relatives back in the north of England. (It's the local Protestant team, although this was never publicly mentioned when I was growing up. John O'Sullivan supported the rival Liverpool FC).